小浪底工程地下厂房混凝土岩壁吊车梁施工

小浪底工程地下厂房区岩石属于层状砂岩，节理发育，在此类岩石中采用混凝土岩壁吊车梁在国内外尚属首次，对于大吨位吊车采用预庆力锚杆加固也是一个创举。本文系统介绍了小浪底工程地下厂房岩壁吊车梁的岩锚台开挖、混凝土浇筑、预应力锚杆的施工工艺和施工方法，为我国岩壁梁施工技术的发展积累了经验。     

棉花滩水电站地下厂房岩壁吊车梁施工质量控制

棉花滩水电站地下厂房岩壁吊车梁是由锚杆和钢筋混凝土联合构成的壁式受力结构，岩壁吊车梁的施工质量将直接影响到以后桥式起重机的安全运行。在厂房第Ⅱ层施工工期紧，岩壁吊车梁施工技术工艺复杂，质量要求高的情况下，采取一系列质量保证及控制措施，如在施工中尤其注意岩壁壁座角的开挖，超挖补强措施，钻孔及锚杆质量，混凝土浇筑及养护等问题，并对锚杆注浆过程和吊车梁混凝土浇筑过程实行旁站监理，确保了岩壁吊车梁施工质量     

南公1水电站地下厂房岩壁吊车梁锚杆施工质量控制

岩壁吊车梁是整个水电站地下厂房施工的关键部位,吊车梁锚杆的施工质量直接关系到岩壁吊车梁的安全性。介绍了南公1水电站地下厂房岩壁吊车梁锚杆施工质量控制采取的有效措施。通过过程控制,保证了岩壁吊车梁锚杆的施工质量。     

天荒坪抽水蓄能电站地下厂房岩壁吊车梁的施工

天荒坪地下厂房采用岩壁吊车梁施工，作者对岩锚梁岩台开挖、锚杆施工、岩锚梁混凝土浇筑及超挖等施工情况进行了介绍。     

仁宗海水电站地下厂房岩壁吊车梁开挖及质量控制

岩壁吊车梁是仁宗海水电站地下厂房施工的关键项目,岩壁吊车梁开挖最重要的是岩台开挖的成型质量,它的好坏直接关系到岩壁吊车梁的整体稳定和使用性能.主要介绍了仁宗海水电站地下厂房岩壁吊车梁的开挖技术及质量控制.     

四川省大渡河金川水电站地下厂房岩壁吊车梁岩台超挖处理措施及锚杆注浆时机研究

为了解决金川水电站地下厂房岩壁吊车梁岩台超挖严重问题,综合考虑现场地质状况、开挖现状、施工条件以及后续开挖可能进一步加剧围岩劣化等因素,对岩台超挖部分实施混凝土回填,并与岩壁吊车梁同期施工。通过建立岩壁吊车梁和回填混凝土及围岩三维有限元数值模型,计算分析了洞室下部开挖过程中的洞壁应力释放和桥机轮压、受拉锚杆注浆时机对岩壁吊车梁受拉锚杆应力以及壁吊车梁应力影响。结果表明：岩壁吊车梁锚固锚杆应力主要受洞壁应力释放影响,轴向拉应力最大值位于岩体中,桥机轮压影响幅度仅为0.32～3.15 MPa;岩壁梁锚固锚杆不宜与系统锚杆同时注浆。岩壁吊车梁运行状态良好,满足稳定要求。     

特大型地下厂房岩壁梁锚杆和混凝土施工技术及质量控制

岩壁梁是一种新型结构，为通过一定深度的锚杆将钢筋混凝土梁固定在地下厂房两侧的岩壁上，而吊车荷载则通过锚杆和钢筋混凝土与岩石接触面的摩擦力传到岩体上，形成岩壁梁和岩体共同受力的结构。岩壁梁是地下厂房施工和运行的核心建筑物，岩壁梁锚杆和混凝土的施工质量是直接关系到岩壁梁成败的关键，所以施工技术和施工质量均要求极高，是地下厂房系统施工的重点和难点。本文介绍了瀑布沟水电站地下厂房岩壁梁锚杆和混凝土施工的关键技术及质量控制经验，可供同类工程借鉴参考。     

白鹤滩水电站地下厂房岩壁吊车梁受力锚杆施工技术

白鹤滩水电站是目前已建和在建最大规模水电站工程,主厂房设计尺寸达地下厂房世界之最,地下厂房工程跨度大、埋深大、地质结构复杂,岩壁吊车梁(简称"岩壁梁")是主厂房中受力最大的结构,岩壁梁受力锚杆施工质量直接影响到岩壁梁结构稳定乃至桥机运行安全,确保岩壁梁受力锚杆施工质量意义重大。结合白鹤滩水电站左岸地下厂房岩壁梁受力锚杆施工情况,介绍大型地下厂房岩壁梁受力锚杆施工技术,以期对今后大型地下厂房岩壁梁受力锚杆施工提供经验借鉴。     

地下厂房岩壁吊车梁结构研究

在考虑西龙池抽水蓄能电站工程地形，地貌，地质条件，岩性，断裂带等因素的基础上，用非线性弹塑性有限元方法对岩壁吊车梁结构进行了系统的研究，并详细分析了岩壁吊车梁施工与运行期的围岩变形，应力以及稳定性，研究结果表明：西龙池抽水蓄能电站地下厂房的开挖施工引起的围岩变形符合一般的地下硐室开挖规律，岩壁吊车梁施工与运行没有异常的变形；岩壁吊车梁施工及运行对围岩应力以及屈服域均不构成影响，岩壁吊车梁锚杆对吊车梁稳定起决定性作用；像西龙池抽水蓄能电站这样围岩以Ⅲ类为主的地下厂房也可采用岩壁吊车梁结构。     

彭水水电站地下厂房岩壁吊车梁高强预应力锚杆二次张拉施工技术

彭水水电站在国内地下厂房中对岩壁吊车梁体系中的高强预应力锚杆首次采用二次张拉施工技术,提高了岩壁吊车梁结构适应下部边墙开挖卸荷变形能力和岩壁梁结构安全度。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。